Hip Dysplasia is a hereditary disease that affects the hip joints of dogs. Hip dysplasia is characterized by a looseness in the hip joint that causes abnormal wear and tear on the femoral head (the ball part of this ball and socket joint) and the acetabulum (the socket). The wear and tear leads to malformation of the ball and socket, and can lead to arthritis. Dogs predisposed to hip dysplasia, unlike children, are born with normal hip joints.
Hip dysplasia can be seen in some dogs as young as five or six months of age. In other dogs, signs do not develop until after the dog matures. Hip pain is generated by the abnormal arthritic bones rubbing against each other. Arthritis will worsen with time unless surgical treatment is administered.
The onset of arthritis can be slow. In fact, sometimes the onset is so slow that you cannot recognize it. Early signs of hip pain in a dog include hopping like a rabbit with the rear legs when running, difficulty in rising from a sitting position, stiffness in the first few steps after lying down, and a reluctance to walk normal distances or play as hard or as long as normal dogs of the same age. Exercise causes these signs to become more prominent. It is important to remember that dogs do not usually cry when they are in pain. Instead, they demonstrate their pain by not properly using the joint or joints that hurt. As the arthritis becomes more severe, dogs will be reluctant to play or go on long walks. Some dogs may not want to walk at all if suffering from severe arthritic pain. Most dogs with hip dysplasia will have both hips affected. Because of this, your dog may not have an obvious limp in one leg because the arthritic pain is more or less equal in both hips.
Radiographs (x-rays) are used routinely to diagnose dogs with hip dysplasia. X-ray changes may be present prior to the onset of clinical signs. Some dogs go through life with no clinical signs but have severe changes seen on their radiographs. It is important to treat the patient and not the radiograph.
Fig. 1: The spherical femoral head (a) fits well with the sufficiently deep bekkenkom (b).
Fig. 2: Bad connection of normally shaped femoral head in the normally shaped bekkenkom.
Fig. 3: The connection of the femoral head in the bekkenkom is insufficient. The head is flat and the bowl is too shallow.
Fig. 4: Flat femoral head, shallow bekkenkom and uncontrolled formation around the head and the bowl.
The primary treatment for hip dysplasia is surgery. Medical treatment and acupuncture can be used to alleviate arthritis pain, but these treatments do not correct the underlying cause of the hip pain.
Currently, there are three accepted surgical procedures for the treatment of hip dysplasia: Triple Pelvic Osteotomy (TPO), Femoral Head and Neck Excision (FHNE), and Total Hip Replacement (THR). Other procedures are available, but these have been found to be ineffective in the long run.
Triple pelvic osteotomy is typically performed in dogs less than twelve months old as an arthritis prevention surgery. This surgery must be performed before arthritis sets in and before the ball or socket is malformed. Dogs with arthritis already present, or dogs with abnormally formed femoral heads or acetabulum’s are not good candidates for this surgery. Since early detection is essential, x-rays should be taken at about six months of age in dogs with clinical signs consistent with hip dysplasia. Surgery involves rotating the socket so that the ball sits more deeply in it. If both hip joints need surgery, the procedures are staged; that is, one side is operated on first and then the other side is operated on later, usually in four to six weeks.
Femoral head and neck excision can be performed at any age and on both hips at the same time. This surgical procedure involves removing the ball part of the joint and positioning the body's normal muscle tissue between the two bones. The body will also lay down scar tissue which helps form a false joint. This procedure is very effective at removing the pain associated with hip arthritis.
Total hip replacement is used primarily for larger dogs. This procedure is very similar to the procedure performed on people. The entire hip is replaced using high density polyethylene for the socket and a cobalt chrome alloy for the ball. This is an excellent procedure for both eliminating the pain associated with hip arthritis and restoring normal hip motion and function. The surgeons at SouthPaws have been performing this surgery for over 10 years with an overall success rate greater than 90 percent.
Once the proper surgical procedure is completed and the dog has recuperated, a full range of activities can resume.